Myopia can be determined in different ways depending on the age of the patient. Adults can make a general judgment by simple distance vision, go to a regular hospital for optometry, and those younger than 12 years old will need additional dilated optometry. Myopia is a type of refractive error, which can be characterized by reduced distance vision. Myopia should be considered when there is persistent blurring of objects in the distance; a definitive diagnosis requires prompt medical attention and appropriate visual acuity and optometry tests. It is worth noting that, if the age of less than 12 years old, the degree of detection is less than 150 degrees, it is necessary to dilate the pupil optometry, to exclude pseudomyopia; in addition, for medium and high myopia, it is necessary to carry out a fundus examination, to check the existence of fundus lesions. In short, if you feel that you have trouble seeing distant objects, you should go to a regular hospital in time for examination and treatment under the guidance of a doctor.